Inhalator with aerosolizing unit

ABSTRACT

A portable, handheld breath actuated inhalator, to aerosolize and distribute a pressurised liquid, including a breath flow path defined between an air inlet ( 132 ) and a mouthpiece ( 131 ) outlet, a container ( 30 ) for the liquid, an aerosolizing element ( 115 ) for introducing the aerosolized liquid into the breath flow path, a valve element ( 113 ) between the container and the aerosolizing means for allowing fluid communication between the container and the aerosolizing element, and an actuator to regulate the valve element. The actuator is mechanical and is energized by the flow of inhaled air.

This application is a 371 of PCT/SE00/02099 dated Nov. 2, 2000.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a portable handheld inhalator for theadministration of a pharmaceutically active substance, and morespecifically to a portable handheld inhalator being actuated by thebreath of the patient.

TECHNICAL BACKGROUND OF THE INVENTION

There is a general need for portable handheld inhalators. A common groupof inhalators are those that deliver an aerosolized drug in a fixed unitdosage when an actuator is pressed, squeezed or pulled by the patient.

It has been found that such inhalators are not optimal in that thedelivered drug is not always introduced effectively into the respiratorypassages of the patient. The coordination between the inhalation and thetriggering of the drug delivery is critical and introduces the risk ofan untimely administration with respect to the breathing. In addition,the breathing cycle and strength differs between different patientswhich introduces another difficulty.

Therefore, breath actuated inhalators have been developed. Suchinhalators are provided with some kind of device that is sensitive to anairflow. Thus, when the patient inhales through a mouthpiece of thedevice, the sensitive device triggers the distribution of the drug. Thedrug is delivered into the airflow, i.e. the patient's inhalation, tocontinue into the respiratory passages of the patient.

Such inhalators, wherein a fixed unit dosage is administered when thepatient inhales, are known, for example through WO 92/09323.

However, even with such unit dosage inhalators it is possible that thepharmaceutics is not inhaled in the most effective way. Therefore,electromechanically actuated inhalators are known that monitors theinhaled air flow and opens and closes, respectively, a valve in responseto the measured air flow, i.e. a continuous administration of the drugis obtained, the length of which is determined by the respectiveinhalation of the patient.

An example of such an inhalator is described in the U.S. Pat. No.5,718,222. With reference to FIG. 17 of said patent, a formulation iscontained in a container that is closed by a valve. When a control unithas received a signal from a flow sensor being connected to themouthpiece of the device, thereby indicating that the patient isinhaling, an actuator opens the valve in response to a signal from thecontrol unit. With the valve open, the formulation enters into aresonance cavity where it is excited by a vibrating electromechanicalmechanism to force the formulation through a membrane. The formulationexits from the membrane in an aerosolized state to be inhaled by thepatient.

In order to obtain an aerosolization with very small and well-defineddroplets the membrane of the device according to U.S. Pat. No. 5,718,222is a so called Rayleigh type membrane. The Rayleigh flow phenomena iswell known within the art, and is for example described inHydrodynamics, Horace H. Lamb, 6th edition, p. 472-475, DoverPublication, New York, 1945.

An example of a breath activated inhalator utilizing a Rayleigh typemembrane is described in the patent U.S. Pat. No. 5,718,222 referred toabove. According to this patent, a pressurised liquid is propelledthrough the membrane.

Thus, although the inhalator according to U.S. Pat. No. 5,718,222addresses the problem of drug administration controlled by the breath ofthe patient, it requires an electromechanical arrangement. This is adisadvantage in many applications, where low cost and small size isdesired. In addition thereto, the need for electric energy makes thedevice vulnerable under circumstances where new batteries or an externalenergy source are not obtainable.

Therefore, there still remains a need for an all-mechanic breathcontrolled inhalator for continuously administering a drug when thepatient is inhaling above a predetermined flow rate. The term“all-mechanic” is not to be regarded as excluding electric or electronicmeans and parts which facilitates the use of the inhaler, such as forexample electronic display means, means for electronically monitoringthe inhalation quality.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a device in responseto the need described above.

According to the invention, a mechanical breath actuated inhalator isprovided. Due to its mechanical working, the inhalator requires noexternal energy source, which makes it reliable under all circumstances.

A mechanical inhalator according to the invention, such as an inhalatoraccording to any one of the embodiments shown in the detaileddescription, allows the manufacturing of a reliable inhalator at arelatively low cost.

Furthermore, the present invention makes it possible to design aninhalator for “puffing” a pharmaceutics, i.e. a certain dosage of apharmaceutics could be inhaled by several breathings in stead ofinhaling the entire dosage in one single breath. For example, thisallows a patient to inhale nicotine in a way that very much resemblessmoking.

In addition, the inhalator could be designed to very small dimensions,thereby allowing a discrete way to inhale a pharmaceutics. In apreferred embodiment for use in anti-smoking treatment, the inhalatorcould be formed with a size and shape similar to a cigarette.

The present invention, as well as further scope of applicability, willbecome apparent from the detailed description given hereinafter.However, it should be understood that the detailed description andspecific examples, while indicating preferred embodiments of theinvention are given by way of illustration only. Various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is described with reference to the accompanyingdrawings, which are given by way of illustration only and thus are notlimiting the present invention, and wherein

FIG. 1 is a perspective view of a first embodiment of an aerosolizingunit according to the present invention.

FIG. 2 is a perspective view of the aerosolizing unit of FIG. 2, viewedfrom a second position.

FIG. 3 is a perspective view of a complete inhalator according to theinvention.

FIG. 4 is a cross sectional view of the inhalator according to FIG. 3.

FIG. 5 is an enlarged cross sectional view through the mouthpiece of theinhalator of FIG. 3.

FIG. 6 is a perspective view of a second embodiment of an aerosolizingunit according to the present invention.

FIG. 7 is a cross sectional view through the mouthpiece of an inhalatorwith the aerosolizing unit according to FIG. 6.

FIG. 8 is an enlarged cross sectional view through the mouthpiece andthe upper part of the aerosolizing unit of FIG. 6, showing theaerosolizing unit in a first position wherein the drug administration isprevented.

FIG. 9 is an enlarged cross sectional view corresponding to FIG. 8,showing the aerosolizing unit in a second position wherein the drugadministration is allowed.

FIG. 10 is a cross sectional view through the mouthpiece and a thirdembodiment of an aerolizing unit according to the invention.

FIG. 11 is a perspective view of the aerolizing unit of FIG. 10.

FIG. 12 is cross sectional view taken along line XII—XII of FIG. 11.

FIG. 13 is cross sectional view taken along line XII—XII of FIG. 11.

FIG. 14 is a cross sectional view of the mouthpiece and a variant of theaerolizing unit of FIG. 10.

It should be noted that terms related to direction, such as “uppersection” or “downward direction”, are used in the description fordistinctive purpose and are typically related to a corresponding figureof the drawings. Thus, such terms should not be understood as limitingthe scope of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In an inhalator with an aerosolizing unit according to the invention aforce is developed by a flow of air, i.e. the inhaled breath of thepatient, said force via a mechanical actuating means acting on a valvemeans to open the valve as long as the flow of air is above a selectedparameter, such as a flow rate or a pressure.

As long as the valve is open, a pressurised liquid such as apharmaceutically active drug is aerosolized and delivered to the flow ofair to be adminstered into the air passages of the patient. The deliverycontinues until the selected parameter of the air flow has decreased toa certain level under which the mechanism no longer manages to keep thevalve open. Typically, the level which the air flow has to exceed toopening the valve is essentially the same as the level below which thevalve closes.

The opening as well as the closing air flow level or levels is/aredetermined by the cooperative dimensions of the elements forming thevalve means and the valve actuating means, as will be described.

A first embodiment of an aerosolizing unit 10 according to the inventionfor use in an inhalator is shown in FIGS. 1 to 6.

FIG. 1 shows the aerosolizing unit 10 from an angle wherein a flexiblemembrane 14 mounted at one side of on a body 19 is visible, as well as agenerally tubular conduit, i.e. a hollow needle 18, for coupling aliquid container thereto. The body 19 consists of an upper body section19A and a lower body section 19B.

FIG. 2 shows the other side of the aerosolizing unit 10 of FIG. 1,wherein a porous membrane 15 is visible. The aerosolizing unit 10, whichis adapted to be mounted in a generally tubular air conduit by means ofa couple of protruding fastening means 22, will now be described indetail.

An embodiment of a complete inhalator 20 according to the inventionincluding the aerosolizing unit 10 of FIGS. 1 and 2 is shown in theperspective view of FIG. 3. The inhalator has an upper section 33containing a drug container (not visible in FIG. 3), a lower sectionforming a mouthpiece 31, and a connecting means 36 for releasablyjoining the upper section 33 with the mouthpiece 31. Holes 24 forreceiving the fastening means 22 of the aerosolizing unit 10 areprovided.

FIG. 4 shows a cross sectional view of the inhalator 20 of FIG. 3. Acartridge 30 containing the liquid to be aerosolized, i.e. typically adrug including a liquid containing a pharmaceutically active substance,is attached to the aerosolizig unit 10 via the hollow needle 18. Theneedle 18 is inserted through a penetrable membrane at the proximal endof the cartridge 30. At the distal end of the cartridge 30 an end wall35 is sealingly slidable. Thus, when an external force is applied tourge the end wall 35 into the cartridge, at the same time as the outletat the proximal is obstructed, the liquid pressure in the cartridge isincreased.

The upper section 33 of the inhalator; which is attached to themouthpiece 31 in a releasable manner using for example a thread or abayonet fitting 36, comprises a piston 37 and a coil spring 38 beingsupported by an end member 39. Air inlet openings 32 are provided in theupper section 33.

When the upper inhalator section 33 and the mouthpiece section 31 aremated, the piston 37 urges the slidable wall 35 of the cartridge 30inwards by the bias of the spring 38. The length and diameter of thepiston 37 as well as the spring force of the spring 38 and itsconnection to the piston are adapted to provide a liquid pressure in thecartridge 30.

The enlarged cross sectional view of FIG. 5 shows the mouthpiece 31 andthe aerosolizing unit 10 contained therein.

The inhalation of the patient creates a flow of air through a flow pathextending through the inhalator, from the air inlet openings 32 to themouthpiece outlet 34. When passing the aerosolizing unit 10 the flow ofair is generally parted into a first flow path FP1 at one side of theaerosolizing unit 10 and a second flow path FP2 at the other side ofaerosolizing unit 10.

As described above, the hollow needle 18 of the aerosolizing unit 10 isinserted into the pharmaceutics cartridge 30 to allow the pharmaceuticsto enter into the aerosolizing unit 10 via the lumen of the needle 18.The lumen of the needle 18 is in fluid communication with an end of achannel 21. The other end of the channel 21 is sealed by a sealingmember 13, thereby preventing the liquid to enter into a chamber 12 alsoin the case when the liquid is under pressure from the piston 37.

The sealing member 13 forms a valve means for allowing and disrupting aflow of liquid out of the channel 21. The sealing member 13 is made froma permanent magnetic material or includes such a material.

A mechanical means for actuating the sealing member 13 comprises amagnetic member 16 being attached to a flexible membrane 14 forinteraction with the magnetic material of the sealing member 13. Byforming the upper and lower body section from a non-magnetic material,such as a suitable polymer, the magnetic member 16 is allowed tointeract with the sealing member 13.

The magnetic field strength and polarities of the sealing member 13(first magnet) and the second magnetic member 16, respectively, areselected such that the members repel each other with a force high enoughto counteract the pressure force of the pressurised channel 21 when no,or a very small, air flow is acting on the membrane.

The membrane, that is formed from a suitable flexible material such asan elastomer, is shown having a generally dome-shaped form (althoughother forms are possible) and its edge(s) is attached to the body of theaerosolizing unit 10. The outer surface of the membrane is disposed in afirst flow path FP1 through the mouthpiece 31. The other side of themembrane 14 is also, via a channel 17, in fluid communication with theair in the mouthpiece. However, the air in the channel 17 is essentiallystatic with respect to the air flowing in the flow path FP1.

As is shown with hidden lines (dot lines) in FIG. 5, the chamber 12 isvia a channel 23 through the body 19A, 19B in communication with anoutlet opening 11 at the opposite side of the aerosolizing unit 10 withrespect to the membrane 14. The opening 11 is covered by the porousmembrane 15 being provided with through pores of microscopic sizes. Itshould be noted that the microscopically small pores are not indicatedin FIG. 5, although they are symbolised with dots in FIG. 2.

The membrane 15 is preferably a Rayleigh type membrane having pores witha diameter in the range of about 0.25 to 6 μm. The specific dimensionand shapes of the pores should be selected to suit the specificpharmaceutical drug, for example based on directions given in thepublication “Hydrodynamics” per above.

However, other types of membranes as well as nozzle arrangements couldof course be used in connection with the invention to aerosolize thedrug.

The porous membrane 15 is exposed to a second flow path FP2.

In use, the patient inhales through the end of the mouthpiece 31,thereby creating a flow of air from the air inlet opening 32 via thefirst and second flow paths FP1, FP2 and into the mouth of the patient.

According to FIG. 5, the air flow in the first flow path FP1 creates alower pressure on the outside of the membrane 14 than on the inside ofthe membrane 14. Therefore an outwardly directed force is created thaturges the central part of membrane 14 out from the body of theaerosolizing unit 10. Since the second magnetic member 16 is fixed tothe inside of membrane 14 it follows the membrane outwards.

When the air flow across the membrane reaches a sufficient strength,i.e. a sufficient flow rate, the membrane and consequently the secondmagnetic member are displaced a sufficient distance from the sealingmember 13 for the magnetic field strength, being approximatelyreciprocally proportional to the square of the distance, no longer to bestrong enough to urge the sealing member 13 to seal the channel 21.Consequently, the size and the bending stiffness of the membrane shouldbe correlated with a desired opening air flow rate to open the channel21 at a proper flow rate to provide optimal inhalation efficiency.

Thus, when an air flow of a certain flow rate sweeps over the flexiblemembrane 14, it lifts the membrane to allow the channel 21 to open, andin consequence the pressurised liquid of the cartridge 30 enters thechannel 12 to reach the porous membrane 15 via the channel 23 and theopening 11.

When the channel 12 is filled with pressurised liquid, and as long asthe sealing element 13 is lifted above the channel 21, liquid will beforced out through the pores of the membrane 15. Outside of the porousmembrane 15 Rayleigh type droplets are formed to be emitted into theairflow of the second flow path FP2. Consequently, the drug droplets arecarried away by the airflow and into the patient's respiratory passagesas desired.

When the airflow over the flexible membrane decreases below a closinglevel, which in the present embodiment is essentially the same as airflow necessary to open the valve means 13, the flexible membrane 14returns to approach its initial position. Consequently, the magneticforce on the sealing member 13 is increased until the sealing member 13again closes the channel 21. Substantially at that moment the output ofdroplets from the porous membrane 15 ceases.

The distribution of liquid according to the description above could berepeated as long as there is liquid under pressure in the channel 21.

Of course, it is possible to design the complete inhalator as adisposable inhalator, but for both economical and environmental reasonsit is preferred to make the aerosolizing unit and the inhalator casingas multiple use components, while the cartridge is a disposable. Thus,when a cartridge 30 is emptied, the upper section 33 is disconnectedfrom the mouthpiece 31 to expose the empty cartridge, which then can bereplaced by a fresh cartridge.

Although the mechanical actuating means of the first embodiment has beendescribed comprising two magnetic members repelling each other, it is ofcourse possible to arrange them in a different way. For example, byplacing the actuating means at the other side of the channel 21, inrespect to the valve means 13 as seen in FIG. 5, and also change theposition of the porous membrane 15, the magnetic members could bearranged to attract each other in stead.

A second embodiment of a handheld portable small size inhalatoraccording to the present invention shall now be described with referenceto FIGS. 6 to 9.

In the perspective view of FIG. 6 is shown a second embodiment of anaerosolizing unit 110 to be attached to the mouthpiece of the inhalatorby fastening means 122. A generally tubular conduit, i.e. a needle 118for coupling to the drug cartridge is attached to the body 119 of theaerosolizing unit 110. A porous membrane 115 for delivering the drug inan aerosolized form is visible at the end of the body 119.

The aerosolizing unit 110 of FIG. 7 shall now be explained withreference to the cross sectional views of FIGS. 7, 8 and 9. Also,reference is made to the first embodiment as described above for theunderstanding of corresponding features.

The unit 110 is mounted within a mouthpiece 131 using the fasteningmeans 122. The mouthpiece is hollow to provide a flow path for inhaledair. At its upper end the flow path exhibits a first section of adiameter D1, and downstream of the first section the flow path widens toa second diameter D2, i.e. D2>D1.

A drug cartridge 30 is mounted on the needle 118 to provide the drug toan inlet channel 141 extending through an upper section of the needle118. The inlet channel 141 is parted from an outlet channel 142 of theneedle by a barrier 143. A first opening 144 provides communicationbetween the inlet channel 141 and the outside of the needle 118.Similarly, a second opening 145 provides communication between theoutside of the needle 118 and the outlet channel 142.

The end of the outlet channel 142 of the needle 118 is in fluidcommunication with an atomizing device, such as a microporous membraneas described above, via a hollow section 111 of the unit 119.

A sleeve 113 is slidably threaded on the needle 118. A section 146 ofthe sleeve is adapted to provide a sealing over the first and secondopening when the sleeve 113 is in a first position along the needle 118.Furthermore, an annular channel section 147 is provided in the sleeve113, around the needle 118 and adjacent to the sealing section 146.Thus, in a first and sealing position with respect to the needle asshown in FIG. 8, the sealing section 146 of the sleeve 113 acts toprevent the pressurised liquid in the cartridge 33 to exit through thefirst opening 144. In a second position with respect to the needle 118as shown in FIG. 9, the sleeve 113 acts to open communication betweenthe inlet channel 141 and the outlet channel 142 of the needle 118, viathe first opening 144, the channel section 147 and the second opening145. Thus, the sleeve 113, and more specifically the sealing portion146, forms a valve means for allowing and disrupting, respectively, aflow of drug to the aerosolizing means 115.

The sliding movement of the sleeve 113 is counteracted by a spring 148that is inserted between the sleeve and the body 119. The initialresting position of the sleeve 113 corresponds to the first sealingposition as described above.

The sleeve 113 is also provided with a flange portion 149 having adiameter to fit slidably within the first section of a diameter D1 inthe mouthpiece 131.

Inlet openings 132 are provided in the inhalator casing to provide anair inlet during use.

During use, i.e. when the patient inhales through the proximal end ofthe mouthpiece 131, a pressure difference between the upper and lowerside of the flange portion 149 will be obtained. When then pressuredifference is sufficiently high, i.e. the patient inhales strong enough,the sleeve 113 will be urged downwards, and against the spring force ofthe spring 148, towards the body 119 of the aerosolizing unit 110 untilthe sleeve 113 has reached a second position within the part of themouthpiece having an inner diameter of D2.

Thus, provided that the strength of the inhalation is strong enough tocounteract the spring 148 (i.e. the flow rate of the air flow is abovean opening flow rate), the sleeve 113 slides from its first sealingposition to a second position wherein communication between thecartridge 30 and the aerosolizing means 115 is established. Therefore,as long as the sleeve 113 is in its second position aerosolized drug isdischarged through the aerosolizing means 115 to be carried by theairflow into the air passages of the patient.

The force of the spring, as well as the dimension of the individualcomponents of the aerosolizing unit, should be selected such that theinhalation needed to open the valve means 146 also ensures that anefficient drug inhalation is obtained.

The valve function of the sleeve 113 and its sealing portion 146 ensuresthat drug is delivered as long as the airflow through the mouthpiece isstrong enough. When the airflow decreases below a certain limit, in thepresent embodiment approximately being the same as the opening airflow,the sleeve is urged back to its sealing position by the spring 148.

Thus, the sleeve 113, i.e. its sealing portion 146, not only forms avalve means but also, in cooperation with the mouthpiece and the spring148, forms a valve actuating means.

The cartridge 30 is, in the second embodiment, biased by a piston andspring arrangement in correspondence with the description of the firstembodiment.

FIGS. 10-13 show a third embodiment of an aerolizing unit where the samecomponents as the previous embodiments have the same reference numbers.The aerolizing unit 200 is attached in the mouthpiece 31 of the inhalerin a suitable manner via a lower 202 and an upper 204 support piece. Thesupport pieces are attached to each other by two fins or wings 206extending radially from the longitudinal axis 208 of the aerolizingunit, FIG. 11. The lower support piece is arranged with a generallytubular, downwardly protruding holder 210. The end of the holder isarranged with a circumferential recess 212, in which a valve unit 214 isarranged. The valve unit comprises a circular lid 216 with a centralopening 218 connecting to a passage arranged in an elongated tubularpart 220 of the valve unit. Outside the opening a porous membrane 222,preferably a Rayleigh membrane is arranged. The passage has a firstdiameter and accommodates a metallic magnetically affectable ball 224,such as a steel ball. The passage then narrows to a lesser diameter,where the transition constitutes a seat for the ball. In the passagewith lesser diameter, extending through the elongated part, a hollowneedle 18 is inserted. The upper end of the needle is inserted in thecartridge 30 containing the liquid to aerolized. In all, this provides acommunication from the interior of the cartridge to the membrane via theball valve.

Outside the elongated tubular part and the needle, a generally tubularbody 228 is rotatably arranged. The lower end of the tubular bodyextends through the lower support piece and terminates in the vicinityof the valve seat. The lower end is arranged with circumferential magnet230. The lower support piece is arranged with arc-shaped air passages232, FIG. 11. The tubular body is further arranged with two fins orsails 234 radially extending therefrom. The upper surface of the lowersupport piece and the lower surface of the upper support piece arearranged with sloping surfaces extending circumferentially. The lowersupport piece is arranged with two such surfaces 236, 238, one insidethe air passage and one outside the air passage, where a lower ledge 239of the tubular body 228 is resting on the inner surface 238.

The wings 234 may rest on the outer surface, but there may also be acertain gap between them, as will be explained below. The lower supportpiece is further provided with a stop ledge 240 for limiting themovement of the wings.

The upper support piece is arranged with two air passages 242, which areplaced so that are arranged between a fixed and a movable wing,respectively, the function of which will be explained in detail below. Acompression spring 244 is arranged in a housing 246 of the upper supportpiece and acts between this and an upper end of the tubular body.

The function is as follows. In rest position, the tubular body 228 withthe movable wings 234 are positioned such by the influence of thecompression spring 244 that the movable wings are in contact with theledges 240 of the lower support piece. In that position, shown in FIG.10, the magnet 230 is close to the valve seat and the ball 224, wherebythe magnetic forces urge the ball upwards against the valve seat,thereby closing the passage. When a user inhales through the mouthpiece,an air flow is created through the air passages 242 of the upper supportpiece and between a fixed and a movable wing. This creates a pressuredifference over the movable wings, which thereby urges the tubular body228 to rotate around the needle 18 and the elongated part 220 of thevalve unit against the force of the compression spring. The rotationalmovement causes the lower ledge 239 of the tubular body 228 to ride onthe inner sloping surfaces 238 of the lower support piece 202, wherebythe tubular body is moved upwards in FIG. 10. Since the tubular body islifted, so is also the magnet, whereby the distance between the magnetand the ball increases. This in turn decreases the magnetic force on theball. At a certain distance between them, the pressure on the liquidfrom the cartridge 30 exceeds the magnetic force, whereby the valveopens. The pressurized liquid is then forced through the membrane,thereby aerolising the liquid. When the user terminates the inhalation,the force from the compression spring pushes the tubular body againstthe sloping surfaces, whereby the tubular body is rotated back to itsinitial position, which also lowers it. The lowering of the tubular body228 brings the magnet 230 closer to the ball 224 until the magneticforces exceeds the pressure form the liquid, and the valve closes. Ofcourse, if the whole dose of pressurized liquid is emptied during theinhalation, the magnetic forces only have to exceed any eventualgravitational forces.

FIG. 14 shows a variant of the embodiment of FIG. 11. It also comprisestwo fixed wigs 206 attached to the upper and lower support pieces andtwo movable wigs 234 attached to a movable tubular body 228. However, inthis case the lower surface of the upper support piece is arranged withsloping surfaces on which the tubular body 228 rests with an upper ledge239, urged by a compression spring 244 acting between a ledge 260 on thetubular body and the upper support surface, which compression springurges the tubular body and compression spring upwards in FIG. 14.

A hollow needle 18 is inserted into the cartridge 30 and fixedlyattached to the housing of the inhaler. The lower part of the needle isarranged with an elongated tubular member 220, the lower end of whichhas a somewhat larger diameter, where the transition constitiutes avalve seat. A ball 224 is arranged to the valve seat. The tubular body228 extends below the lower end of the tubular member 220 and enclosesit with an end wall 262. The inwardly surface of the end wall isarranged with a support projection 264, which, when the tubular body isin the rest position, pushes the ball against the valve seat. The endwall is further provided with a number of passages 266, which are influid connection with a porous membrane 222, such as a Raileyghmembrane.

The function of this variant is as follows. As described above, thecompression spring 244 urges the tubular body 228 upwards and in itsresting position, the tubular body 228 is resting against the ledges ofthe upper support piece in this case. The ball 224 is now pressedagainst the valve seat and the valve is closed. When a user inhales, thepressure difference over the movable wings, as described above, causesthe tubular body 228 to rotate against the force of the compressionspring. Because the tubular body rests against the sloping surfaces ofthe upper support piece, the tubular body with its end wall and supportprojection 264 is lowered in respect to the needle and the tubularmember. The lowering of the support projection causes the ball to befree from the valve seat thereby permitting the pressurized liquid fromthe cartridge to flow past the valve, through the passages 266 andthrough the membrane 222, thereby aerolizing the liquid.

When the user terminates inhalation, the force from the compressionspring urges the tubular body upwards, and because it is resting on thesloping surfaces, the tubular body will be lifted. The supportprojection is also lifted and pushes the ball against the valve seat,thereby closing the valve.

Even though a ball has been shown and described in the last twoembodiments, it is to be understood that other movable bodies capable offorming a valve unit together with a valve seat are may be employed,such as for example conically shaped bodies. As for the embodimentaccording to FIG. 10, the movable body may also be manufactured of amagnetic material in order to increase the force between the magnet andthe movable body. Preferably the movable body then has a form thatensures a certain orientation so that the magnets cooperate.

The aerolising units shown in the drawings 10-14 are only to be regardedas illustrative examples. The actual units used may have differentdimensions depending on the demands and space available of an inhaler.As regards for example an anti-smoking inhaler, the inhaler body shouldbe long and rather thin, whereby the aerolising unit has to be adaptedaccordingly. As regards the inclination of the sloping surfaces the sizeand placement of the air passages, spring characteristics and the likecomponents affecting the function, these may be altered in many ways inorder to optimizing the performance of the device depending theapplication, the users breathing abilities and such.

Thus, with an inhalator and an aerosolizing unit according to theinvention, a drug is administered to a patient in an aerosolized formusing a portable handheld device.

The drug is delivered continuously as long as the patient inhales with astrength selected to ensure a good inhalation effect.

Except for the force needed for biasing the pressure in the liquidduring the assembly of the inhalator the only power needed to actuatethe valve means is the force developed by the breath of the user. Thus,the user does not need to rely on a separate power source, such as abattery. Of course, embodiments wherein the biasing is performed as aseparate step could be possible as well.

A mechanical inhalator, such as an inhalator according to theembodiments shown, has remarkably few and simple components, and istherefore relatively cheap and easy to manufacture, even in handheldsizes.

The all mechanical inhalator, as regards administering the drug, isreliable in that the user does not have to worry about the freshness oravailability of batteries or any additional sources of energy.

A preferred use of the aerosolizing unit according to the invention iswithin the field of antismoking treatment. Within this field it is knownto treat the patient with nicotine. It has been found that it isadvantageous to provide the nicotine to the patient in a way that is assimilar to smoking as possible.

The aerosolizing unit of the present invention is well suited for such ause, since a small amount of the pharmaceutics is delivered each timethe user inhales with a breath strong enough. Also, the inhalator couldbe designed to resemble the size and shape of a cigarette, as is shownin FIG. 3.

However, in the embodiments of an inhalator as described above, nothingprevents the user from continue to inhale pharmaceutics by successiveinhalations until the container is emptied.

Unless the container holds one dosage unit only, this implies a risk foroverdosing. Also, if a replaceable container holds one dosage only, theneed to change the pharmaceutics container for each treatment might beperceived as uncomfortable and disturbing.

Therefore, it is preferred to provide the pharmaceutics in a multi-dosecontainer. This calls for a dosage mechanism that prevents the user fromunintentionally receiving more that one unit dose.

Two embodiments of such dosage mechanism shall now be described.

A first embodiment of such a dosage mechanism comprises a dose unitcompartment between the cartridge and the valve mechanism (such as thevalve provided by the member 13 of the first embodiment above, or thesleeve 113 of the second embodiment) of the aerosolizing unit. Anadditional valve is provided between the cartridge and the unit dosecompartment. Before inhalation the patient opens the additional valve tofill the unit dose compartment with a unit dose of the drug, and thenshuts the valve. Thus, pressurised liquid of one unit dose is containedin the compartment, and is aerosolized according to the descriptionabove when the user inhales trough the inhalator. To receive a nextdose, the patient has to repeat the loading of the unit dosecompartment. Such a dose unit compartment and additional valve may ofcourse be included in the embodiments according to FIGS. 10-14, eventhough they are not indicated in these.

A second embodiment of a dosage mechanism utilizes the axial movement ofthe piston in the inhalator upper section, used to pressurise anddischarge liquid from the cartridge into the aerosolizing unit. A simplelatch mechanism, wherein a releasable latch is in engagement withrecesses in the piston. The recesses are spaced apart along the piston,spaced from each other with a distance corresponding to the pistonstroke needed to displace one unit dose. Thus, the latch mechanismallows the piston to move only a distance corresponding to one unitdose. When such a unit dose has been inhaled, the patient has tomanipulate the latch to activate the next dose.

With a dosage mechanism as described above, the user sets the dosagemechanism to permit the next unit dose, and may puff, i.e. inhale withsmall inhalations, until the predetermined dose is received. Actually,it is possible to adapt the dosage mechanism to a variable dose settingby using a screw mechanism similar to an insulin injector.

Although the use of the inhalator for introducing a pharmaceuticallyactive substance into a human body has been described above, it is ofcourse possible to use the inhalator for other purposes as well, such asto refresh the breath or to introduce a generally well tasting substanceinto the mouth.

Similarly, the inhalator could be adapted for inhalation through thenose as well as through the mouth.

It is obvious that the present invention may be varied in many ways withrespect to the detailed description above. Such variations are not to beregarded as a departure from the spirit and scope of the invention, andall such modifications as would be obvious to one skilled in the art areintended to be included within the scope of the following claims.

1. A portable, handheld breath actuated inhalator, to aerosolize anddistribute a pressurised liquid, including, arranged in a housing, abreath flow path defined between an air inlet and a mouthpiece outlet, acontainer containing the liquid to be distributed, mechanicalpressurizing means for constantly applying a pressure on the liquid insaid container, a liquid conduit in flow communication with an interiorof said container, an aerosolizing membrane with through pores ofmicroscopic size in said breath flow path and in flow communication withsaid liquid conduit, said aerosolizing membrane aerosolizing thepressurized liquid and introducing the aerosolized liquid into thebreath flow path, a mechanical valve means between said container andsaid aerosolizing membrane for controlling fluid communication betweensaid container and said aerosolizing membrane, thereby controlling theintroduction of the aerosolized liquid into the breath flow path, and amechanical actuating means in said breath flow path, said mechanicalactuating means for opening said mechanical valve means when a firstlevel of an inhalation flow parameter in said breath flow path isreached and for closing said mechanical valve means when a second levelof the inhalation flow parameter is reached.
 2. The inhalator accordingto claim 1, wherein said valve comprises a sleeve (113) surrounding atubular conduit (118) for slidable, sealing movement along said conduit(118), said conduit having a first section (141) in fluid communicationwith the container (30) of the liquid, and said first section (141)having an outlet opening (144), and a second section (142), separatefrom said first section (141), in fluid communication with theaerosolizing membrane (115) and said second section (142) having aninlet opening (145), wherein said sleeve (113) includes a channel (147)and a sealing section (146) arranged such that said sealing section(146) in a first position of said sleeve (113) seals said outlet (144)and inlet (145) openings, respectively, and in a second position of saidsleeve (113) communication is opened between said outlet opening (144)and said inlet opening (145) via said channel (147); and wherein saidmechanical actuating means comprises a flange member (149) connected tosaid sleeve for moving therewith, said flange member (149) beingarranged in the breath flow path to be movable by the action of the airflow to move the sleeve from said first position to said secondposition, and a spring means (148) for returning said sleeve to saidfirst position.
 3. The inhalator according to claim 1, wherein saidinhalation flow parameter is selected from the group consisting of theinhalation flow rate and the inhalation air pressure within the breathflow path.
 4. The inhalator according to claim 1, wherein the firstlevel of inhalation flow parameter is substantially the same as thesecond level of inhalation flow parameter.
 5. The inhalator according toclaim 1, wherein the first level of inhalation flow parametersubstantially differs from the second level of inhalation flowparameter.
 6. The inhalator according to claim 1, wherein said valve(214) comprises a movable body (224) arranged in a passage (218), whichpassage is in fluid communication with the liquid container (30), thepassage having a seat and the movable body and the seat havingcorresponding shapes as to form a sealing connection, said mechanicalactuating means comprises a body (228) rotationally arranged in saidinhalator, the body comprises means (230, 262, 264) for urging saidmovable body against said seat, air flow directing means (206, 232, 234,242) arranged to said body and said inhaler, arranged and designed suchthat, upon inhalation, a pressure difference is created over the flowdirecting means of said body (234), which pressure difference causessaid body to rotate, thereby moving said urging means away from saidmovable body, and opening said valve means.
 7. The inhalator accordingto claim 6, wherein the movable body of the valve comprises amagnetically affected material, and that said urging means comprises amagnet (230).
 8. The inhalator according to claim 7, further comprisingcam-shaped surfaces on which the rotationally arranged body rests, whichcam-shaped surfaces transform the rotational movement of the body to alinear movement.
 9. The inhalator according to claim 7, furthercomprising spring means (244) for urging the rotationally arranged bodyto its initial position after end of inhalation.
 10. The inhalatoraccording to claim 6, wherein said urging means comprises a holdingmember attached to said body and in contact with said movable body. 11.A breath actuated inhalator for aerosolizing and distributing apressurised liquid, comprising: a breath flow path defined between anair inlet and a mouthpiece outlet; a container for the liquid; anaerosolizing membrane for aerosolizing the liquid and introducing theaerosolized liquid into said breath flow path; a valve controlling theintroduction of the aerosolized liquid into said breath flow path, saidvalve being between said container and said aerosolizing membrane andallowing fluid communication between said container and saidaerosolizing membrane; a mechanical actuator regulating said valve andbeing energized by a flow of inhaled air; wherein the valve means is amoveable sealing member for closing a conduit in communication with saidcontainer and comprising a first magnetic member and wherein saidmechanical actuating actuator comprises a flexible membrane moveable inresponse to an air pressure created by the flow of inhaled air and asecond magnetic member connected to said flexible membrane for movingtherewith, wherein said first and the second magnetic members arearranged in a repelling relationship to each other for urging saidsealing member to close said conduit.